Manufacture of hollow metal balls



Feb. 10, 1925.

1,526,140 J. H. GRUVER MANUFACTURE OF HOLLOW METAL BALLS Filed Oct- 5. 1921 2 Sheets-Sheet 1 J Inuentpg Jjgeph ia fy GBuI/Zerx J. H. GRUVER MANUFACTURE OF HOLLOW METAL BALLS,

Fild Oct. 3 1921 2 Sheets-Sheet 2 Inventor.-

J ie uh Harry Granger, 6 3% M %(/moa%, mum/w Atty were Feb. 10, 1925.

N ED I 'PA NT FICE.

arosnr tnnniirennirm, or BALT IMQQEyMe -YMND,assIGrIoR "ro HOLLOW 3511.1. 1 ,QOMBANY,QINCQRPQRATED, OE,IBALTIMORE,YMARYLAND, A CO'RPORATIQN or 3 MAR LAND. 5

ijrIANiIFAc'rURE Q iiIoIIILow Mma'n Bniins.

j; lhpiilicatipn and October 3, 1921. Serial m. 505,083.

GRUV R, acitizen of, the United States, and

resident Of Baltimore,Maryland","have ini nentshin the Manufacture "of Hollow Metal Vented certain new and useful Improvegeneral ohject, improyements in methods andapparatusused inthe manufacture of i i balls themselves; a 7 a In my PatentsNosQ] such balls as well as improvements in the 1,278,914 and 1,278,915,

I have disclosed a method of makinghollow rjnetalTlozills,.' WhiQh comprises in general,

,forming" an? approximately spherical shell fron aQflat metal blank; by a series of fornr ing g emaens; andthen rolling and spinningltheshell thus formed under pressure in relativelxfmovable, cooperating, circular earlier; patents,

grooves insthe ewes of opposed discs, to close a h, i amnesi e shell and improve its spheric-l V ftion relates to certain im rovements in the,

ityf. ,Thefinyentionof the present applicw method and,

ap arat s escribed' l in those a of the present intention I have discovered that thej shape'of the clos efficiency ofthemclosing operation and have ,foundyit advantageous so to form this groove" thatl fi the shell contacts with .it at two n points only; To attain this resultQI make sides, ofsuoh form ithatthe two points of the rollinggrooue with outwardly diverging contact are substantially Below the mouth of at thagmova even at the start ofjthe closin operation thuspreifenting theicntting of the Shelli When-a shell is rolled under ipressure within a) circular groovefof this 'Ineridional sectionglthe groove im artsa gyrating movejinent to the shell an is highly efficient in working and ,spinning the metal of [the shell, closethe hole or .holes left. after the forming operation, knit themetal into a" 5 tifi ll ftantially homogeneous shell,and size the v earlier patents, have described making halls from a blank of fiat metal. For small balls, "that is for balls less'than about 1 inch] I diameter, this method in operations preparatory to rolling. rollingand closing, the finished product thus has two diametrically opposed noleswhere themetal'is knitted together and the ball is *panving' drawincnin which Fig.9 and Fig. 3P arevertical' throughthefireliininary forming dies showquite "satisfactory, "but for the larger sizes,

thernumber of forming operations, preliminary to rolling andlclosing, and the number of annealing and rolling operations must be increased. Moreover, where anicely balanced-ball mustbe obtained, as for certain types of valves, it is diflicult to obtain a size balls and to makea more perfectly balfanced ball. -I attain this object by starting outwith a trimmed tubular blank and partly close the two ends by forming orpressing After more perfectly balanced than if it had but i a single point of closure. In thus making before the forming operation.

prevents buckling during forming. andI am enabled to obtain snbstantiallv uniform wall thICkl'mSSWfllL a minimum. of rolling. mg grooves has an lrnportantbear ng on the h order that the invention may bemore clearly understood, certain preferredfembodirnents of it are shown in the accom- Flg'ure 1 is a longitudinal section through a tnbular blank, which is cut and trimmed fromtubular stock. a

Fig; 2 is a similar View t this blank cong varied into substantially spherical form, but with openings at "opposite sides by means of the dies shown in' Figs. 3*and 3". a a a Fig. 3*is a section through a closed ball which results from taking the ballform of Fig. 2 and closing its openings in accordance with the present invention. I

sections twosteps inthe forming operation. 7 igr4 isa side viewof arollmg machine. Fig.*5 isadetail sectional view of one of the ball rolling plates with its grooves.

Fig eis ayiewin the nature of a diagram of the 'shapehf a pair ofc'losing grooves; i

' shown in Figs. 2 and 3, having which is adjustable operation progresses.

'= the upper Fig. 'l is a view similar to Fig. 6 but showing a modified form of groove. v I in carrying out the invention I tal{e'n1etal tubing, the wall of which is substantially of the same thickness throughout, and from this l cut a section, and at the same time edge and taper it from its center towards either end, as shown at 11 in Fig. 1. This tapered section of tubing is then placed between forming dies, shown in Figs. 3* and 3 ,-which are mounted in a suitable machine, and with one or more pressing or forming operations, according to the size of theshell, l t obtain a blank or shell which is round, as two small holes 12 opposite each other. The shells are subjected to annealing/operations, repeated as may be necessaiy. I

This shell or ball with two holes is next placed in specially formed grooves of a machine illustrated generally in Fig. 4' for closand sizing. The grooves are formed in the faces of opposing discs, the upper oneof towards and from the lower one by hand wheel 3 through caring a, and the lower may be rotated t rough mechanism illustrated in Fig. l. The holes closed and the ball is sized by a rolling spinning action, and this action is given under gradually increasing pressure, as the At rst the. upper die or plate 2 is raised to permit the rough hall-shapes to be introduced into the groove 1 and then by turning the hand-wheel Sat.

La v I portlon of the machine in the proper'direction this upper die 1s lowered througn the gearing, to bear upon these halls.

- duced paratively rapid at the beginning of the pressure on the balls, butas the size is reand the hole closed, the lowering must be slowed down. The. relative po ition of the plates and the size-of the is is indicated on a dial ring 5 and pointor '6 the top of the machine.

"As shown in Fig. 6, the configuration of groove 1 is specially formed. Viewed in cross section, it is made up of segments of circle-s. From to 5, Fig. 6, thearc. is struck from c as a center, and the diameter here is, say, .685 of an. inch. The bottom of the groove, i. e., the part lying between the points -4), is struck on a radius (giving a diameter or, say, .625) from center (1. The

rough ball shape, when first introduced into this groove, is represented approximately by the dotted circle c. It will thus be seen that from the mouth of the groove to substantially hair way to the bottom thereof the radius is larger than the shell or ball when placed in the groove. From substantially hair the depth to the bottom of the groove, the radius is substantially that of the radius of the ball when the operation is completed.

"in these grooves of the upper and lower The lowering movement may he complane nearly half depth of'th'e groove when the ball or shell is placed in the grooves although the ball does not touch the bottom of the grooves. The two points of contact in each groove are less than 180 apart. When pressure is exerted on the shell or ball by the grooved discs between which the balls are located, owing to the tapering of the shell and the special configuration of the groove, a movement of metal starts from desired partsv of the wall, and goes towards the holes in such a manner that the holes are closed to the full thickness of the wall, the particles of metal tightly knitting together, and the wall of the ball being thickened to the desired degree, andl produce a ball that is of the same strength at all parts and perfectly balanced. v y I anneal the shell or ball before placing it in the grooves and do not confinemyself to one rolling or annealing." 4 The groove for sizing theball and closing the openings therein may be of the form way of the depth of the groove to the bottom thereof, the wallfollows a segment'of a circle, the radius of which is substantially that of the ball when the operation is completed. When the ballcom'es from the closing' and sizing grooves'it may not be perfectly spherical. As a finishing operation, I place it between the shallow finishing grooves 7 which grooves are circular in cross-section vcut on a circle of larger diameterthan the ball so that each groove contacts'with the ball at one point only. I

By the use of a closing groove of the con figuration described or its equivalent the balls are caused to constantly change as to the position oi their. aXis of rotation so that they do not rotate about an axis always disposed horizontally. This would beundesirable because then the balls would roll only on their top and bottom portions like a 1 wheel. turning about a horizontal axis. lVith the four point bearing however, in which two of the points are travelling faster, than theircompanion points'by reason of their greater distance from the center of rotation the ball form is given what may be called a gyrating movement and all parts are brought under the action of the walls of the groove causing the'metal to flower" move from all directions towards the axis of-the opening or openings so that eventually the ball is completely closed. The invention is not limited to the use of rotating'discs as other forms of grooved members may be employed to give the ball its universal rotary hase: been proposed toma-ke a shell from metalj'ktubing :with .holes, 'atj'opposite points to receive-a rod or balustenbut inthat profv posal afitubeitapered toits endswas ag, 1 gested, neither-was a 'completely closed ,hol;

entaofi theAUnitediStates granted ,toflBr'andt" low. sheefimetal ballj posali am also; aware of. the LettersPat- 1 N0.2QZ,1,58, August 20,1878, which discloses the grooves being in factsmall areas of jecting such blankto reforming the revelution, open, shells or f ballsflin y grooved plates under, pressure in orderito other P1 he su f ce o s idgs el s,

lf] 'tion, the ob'ect therebeiiig to obtain a bearns enes muchre e l es PQsSibI -Q So fares I I claim: 1." The herein describedmethod of making hollow balls, consisting in forming a blank from. a section of metal tubing by tapering,

it from its center towards either end, sub operations in forming dies, to form an incompletely closed, approximately spherical shell and then revolving said shell under pressure in grooves, until the holes are closed to the 'full sired degree. i y

2. Apparatus; for rolling hollow metal shells or balls to close their openings and size them,

thickness of the wall, the metal tightly knitted, and the wall thickened to the decomprising two grooved members having relative movement, the groove in each member having ltSbOttOIIl curved on a radius substantially equal to the radius of the finished ball, saidbottom curve starting well down within the groove, and the concave wall from the top of this bottom curve to the mouth of the groove being on a curve whose radius is greater thanthe radius ofthe said bottom curve, substantially as described.

e0 shells or balls to close size them,

3. Apparatus for rolling hollow lmetal their openings and comprising two grooved members having relative movement, the groove in each member having its bottom curved on a radius substantially 'equalto the radius of part of. this prior pro-- The shells and the closed balls -with outwardly diverging tacting with each ball below the mouth of points only, these points the finished ball, said bottom curve. starting sllbstantiallvhalf way 1 within the "groove, andthe. wallsfof the groove from the mouth beingalong lines diverging outwardly." 1 41;, Apparatus for rolling and sizing hol low in'etal balls, comprising the combination of two grooved members having relative movement, the groove in each member haw i ingside walls which'diverge outwardly from QQZOI'IB substantially half-way between "the mouth and bottom of the groove, and mak ing only a two-pointcontact with the ball, bj1 th mo t e the sl e A 1 5 The" m thlod, ff makinghollow' metal balls which comprises forming an ap roximately spherical incompletely closed shell, and imparting 1a g'y rating rolli gmetionat said, shell under groove which "contacts with the shell attwo points only, to close the opening or openings in the shell and reduce it to size, the points of thisbottom curve to the top of thegroove pressure within an open of contact-being below the mouth of the t groove and less than 180 apart.

6; The method of making hollow metal balls which comprises forming an approximat-ely spherical incompletely closed shell, and imparting a gyrating rolling motion to said shell under gradually increasing pressure within an open groove which contacts with the shellat two points only, to close the I 1 opening or openings in the shell and reduce it to size, the points of contact being below the mouth of the groove and. less than 180 apart.

7. The method of making hollow metal balls whichcomprises forming an'approximately spherical incompletely closed shell,

and imparting a gyrating rolling motion to said hell under pressure within two mutually opposed grooves, eachof which makes only a two-point contact with the shell bei openingor openings in the shell and reduce it to sue.

low metal balls comprising thecombination of a disc having in its face a circular groove side walls conthe groove .at two being less than 180 apart, and'means cooperating with said disc to roll the balls within the groove under pressure.

9. Apparatus for rolling and. sizing hollow metal balls comprising the combination of two discs provided in their faces with cooperating ball-receiving circular grooves having outwardly d verging side walls, each groove making only a two-point contact with the ball below the mouth of each groove, 'means for imparting relativerotation to said discs, and means for exerting pressure between said discs to compress the balls.

low the mouth of each groove. to. close the Apparatus for rolling and s zing hol- 10. Apparatus for rolling and sizing hollow=metal balls comprising the combination of two discsprovided in their faces with cooperating l allreceiving circular grooves having outwardly diverging side walls, each groove making only a. two-point contact with the ball belo v the mouth of each groove, means for imparting relative rotation to. said discs, means for moving'said discs toward each other to compress the balls, and means for indicating the relative position of the discs.

11. A balanced meta ball, having Walls of substantially uniform thickness and'made from a piece of tubing bv tapering it from its center' towards its en s,'forming it into an approximately spherical, incompletely closed shell, and Working the shell ,under pressure to close the openings therein and knit the metal. V c y 12. The method-of makinghollowballs,

consisting in forming a blank from a section of metal tubing by tapering it from its center toward either end, subjecting such blank to forming operations to provide a ball having openings therein, and mechanically flowing together tlic metal surrounding said openings 'to close the same and provide a ball having seamless, homogeneous Walls, and simultaneously shaping said ball during the metal flowingoperations.

13. Apparatus for rolling and sizing hollow metal balls comprising the combination of a disc having ts facea circular groove With outwardly diverging side wallsmakmg only a two-point contact with the balls below the mouth of the groove, and a second grooved disc cooperating with the first disc to roll the balls within-the grooves under pressure. i i

In testimony whereof, I aflix my signature.

JOSEPH HARRY GRUVER. 

